The invention is directed to an apparatus and to a method for the centrifugal wet-mechanical separation of solids based on their density using a rotating container that is provided with openings for the admission of the solids to be separated and for the discharge of the separated solids and a parting liquid, and having a rotating discharge means, such as a rotating screw conveyor, arranged in the container.
The wet-chemical separation of solids based on their density in a centrifugal field of a rotating container is disclosed in U.S. Pat. No. 2,528,974. In this known method, ores are separated based on their density in an apparatus fashioned as a centrifuge, whereby the ore is separated in a plurality of density stages between the final values of less than 4.0 g/cm.sup.3 through more than 7.2 g/cm.sup.3 by varying the density of the parting liquid. The centrifuge employed for this purpose comprises two oppositely coiled screw conveyors arranged on a shaft as a discharge means, these conveying the floating matter to one side and the sinks (higher density materials) to the other side of the centrifuge. The discharge opening for the parting liquid is situated next to the discharge opening for the floating material, likewise at an end of the centrifuge.
What is disadvantageous with separating device disclosed by U.S. Pat. No. 2,528,974 relates to the design of the discharge means which, due to the opposite coiling of the screw conveyors, leads to undesirable turbulances in the parting liquid, as well as the misplaced discharge of floating matter at the sinks discharge, caused by the proximity of the admission opening for the ore suspension relative to the discharge opening for the sinks.